• Title/Summary/Keyword: distribution of alluvial fan

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The Geomorphic Development of Alluvial Fans in the Cyeongju City and Cheonbuk area, Southeastern Korea (경주 및 천북 지역의 선상지 지형발달)

  • 윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.39 no.1
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    • pp.56-69
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    • 2004
  • We investigated the distribution and geomorphic development of alluvial fan in Gyeongju City including Cheonbuk area. According to a relative height to a river bed, alluvial fans of this area are divided into Higher surface, Middle surface, and Lower surface. As alluvial fans of Bulguk temple∼Ulsan bay area, the confluent fans in Cheonbuk and Gyeongju areas were formed by the Quaternary climatic change alternating glacial and interglacial stages, and the development of N-S and NW-SE fault lines. The Gyeongju alluvial fan, the largest in Korea, has been provided as the significant space for human activity since the prehistoric age. Bukcheon river formed the Gyeongju alluvial fan had not flowed over during the prehistoric and the ancient times. In contrast with general geomorphic characteristics, many springs in the Gyeongju alluvial fan are located in the middle part of the fan because ground water reaches to the surface. It is supposed that sedimental materials were not sufficiently piled up at lower reach of Bukcheon river due to the large deposits at upper and middle reach of the basin.

The Ceomorphic Development of Alluvial Fans in Cheongdo Basin, Gyeongsangbuk-do( Prevince), South Korea (경북 청도분지의 선상지 지형발달)

  • Hwang Sang-Ill
    • Journal of the Korean Geographical Society
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    • v.39 no.4
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    • pp.514-527
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    • 2004
  • We investigated the distribution and geomorphic development of alluvial fans at Cheongdo- and Hweyang-eup(town) in the Cheongdo Basin, Gyeongsangbuk-do(Province) of Korea. The alluvial fans of study area are formed confluently to the E-W direction at the northern slope of the Mt. Namsan(840 m). They are classified into Higher surface, Middle surface, and Lower surface according to a relative height to a river bed. And the older alluvial fan is, the deeper gravel in the stream deposits is weathered. The magnitude of each surface composing of confluent fans is related to that of the drainage basin. So called fan-basin system of magnitude on the study area is on the positive(+) relation in the study area. The large fans over 1km in radius are found on the basin of andesite rock which is resistant to the weathering and erosion. Moreover there is no tectonic movement in the basin. It means the most important element influenced on the fan formation is not tectonic movement, but the Quaternary climatic change, which is the periglacial climate alternating glacial and interglacial stages during the Quaternary. Therefore alluvial fans would distribute in Korea overall influenced by the Quaternary climatic change.

A Study on the Status of Use and Value of 'Saemi' in Sacheon Alluvial Fan (사천 선상지 '새미'의 이용 실태 및 가치 고찰)

  • Kim, Dohyun;Jeong, Myeong Cheol;Seo, Ki Chun
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.4
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    • pp.85-95
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    • 2022
  • This study is about the story of 'Saemi', existing in the Sacheon Alluvial fan area. Saemi is a local word for Dumbeong, which is the traditional water irrigation facilities in this area that could be formed according to the geographical characteristics of a Alluvial fan site. In the meantime, although Saemi has been an important source of water, related research has been mainly done from an ecological point of view. Accordingly, the researcher paid attention to the functional aspects of Saemi itself, grasped its location, distribution status, and usage including the construction method, and considered its intrinsic value through classification and characteristic analysis of Saemi. As a result of five field surveys from September 2021 to October 2022, 129 Saemies remained in the Sacheon alluvial fan area. According to the structure and shape, Saemi could be divided into basic type, complex type, and buried type. The basic type was subdivided into bucket-type and stairs-type along with the complex type, and the buried type was subdivided into all buried-type and some buried-type. Saemies were mainly distributed at the distal end of the Sacheon alluvial fan site, individual Saemies were built on farmland, and common Saemies were usually built along roadsides adjacent to villages. The reason why the Saemies are concentrated at the distal end is the geographical characteristics of the alluvial fan where the water underflows. Saemi was an important multifunctional water supply source equivalent to the main water source for people at the distal end of the pond who did not receive a stable supply of water from the reservoir. Saemi was at the center of the underground water irrigation network agricultural system in the Sacheon alluvial fan area according to the principles of 'bbaeim(drop out)' and 'gaepim(pooling)' It has provided a foundation for establishing itself as an appropriate technology in this area. Such Saemi contributed to the rural landscape and agricultural biodiversity through its own system and served as a public interest function. It is necessary to know, conserve, manage, and continuously utilize the value of this Saemi as an agricultural heritage.

Survey of Geomorphological Resources of 'Daegu Innovation Town' Development Plan Area (대구 혁신도시 개발예정지의 지형자원 조사)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.14 no.2
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    • pp.173-188
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    • 2008
  • In order to make comparative analysis of geomorphological changes caused by urban development, I surveyed the distribution of geomorphological resources of 'Daegu Innovation Town' development plan area. The results are as follow: (1) At the front of small valleys of back-mountains are formed small alluvial fans, and at the side of small valleys are distributed hills connected with back-mountains. (2) As small valley erode laterally hills, vertical bluffs and planner bedrock riverbed are formed, and in some riverbed are appeared mud cracks and ripple marks. (3) The depth of valley in alluvial fan of 'Sinseo District' is 7m. In Sinseocheon valley dissecting alluvial fan, fluvial terraces 2m high above riverbed are distributed. Those terraces were formed while alluvial fan was dissected after last glacial period.

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The Distribution and Geomorphic Development of Alluvial Fans along the Bulguksa Fault System in Gyeongju and Ulsan City, Southeastern Korea (한국 남동부 경주 및 울산시 불국사단층선 지역의 선상지 분포와 지형발달)

  • 황상일;윤순옥
    • Journal of the Korean Geographical Society
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    • v.36 no.3
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    • pp.217-232
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    • 2001
  • One of the molt debatable Issues on geomorphological study in Korea should be the discussion over the formation process of gent1e slope surfaces on the piedmont area. In this study, the characteristics of spatial distribution and the formation process of geomorphic surfaces were investigated by classifying the alluvial fans as three geomorphic surfaces alluvial the Bulguksa fault-line The fan surfaces, distributed along the west slue of Bulguksa Mts, consists the confluent alluvial fans continuously along the N-S direction The surfaces of Sincheon-Hyomun district juxtaposed to the Ulsan Bay must be infulenced by sea-level chance during the Quaternary Taken together, these observation suggests that the major four factors contributed to the fan formation 1) rather longer freeze-and-thaw cycle during the Glacial period. 2) the steep mountain slope along the west side of Bulguksa Mts.. which had been resulted from the horizont stress of EAst Sea 3)the tectolinear fault system developed by structural movement along the Bulguksa Fault-line valley. and 4) the erosion-labile characteristics of bedrock In this urea which is consisted of the Bulguksa granite and the sedimentary rock formed in Cretaceous period.

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Competitiveness of 'Saemi' in Sacheon Alluvial Fan as a Cultural-ecological Niche (문화생태적 적소로서 사천 선상지 '새미'의 경쟁력)

  • Dohyun Kim;Myeongcheol Jeong;Kichun Seo
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.516-532
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    • 2023
  • This study is the result of analyzing the distribution of 129 Saemies discovered based on field research conducted from September 2021 to June 2023 in the Sacheon alluvial fan area through ethnoscience and niche theory. The researcher viewed the Sacheon alluvial fan area as a suitable location for irrigation where both traditional and modern hydraulic facilities are used, and the cultural and ecological study of 'Saemi', a traditional irrigation facility that attracts attention for its public value for the ecological environment according to the sustainable paradigm. By revealing its competitiveness, we aimed to contribute to finding ways to sustainably conserve and utilize Saemi. As a result of the study, Saemi is confirmed to be a competitive water facility in terms of cultural and ecological quality, considering the direction of the times and the sustainable development. If environment-friendly agricultural technology is applied to traditional water treatment facilities in the context of sustainable agriculture, it is expected that synergy will be created in productivity, public interest, and sustainability.

Structure and Physical Property of the Crust of Mid-west Korea: Analysis of Sedimentary Basins in the Namyang and Tando Areas, Kyeonggi Province, Korea (한반도 중서부 지각구조와 물성 연구: 경기도 화성군 남양 및 안산시 탄도지역에 분포하는 퇴적분지의 분석)

  • Park, Sung-Dae;Chung, Gong-Soo;Jeong, Ji-Gon;Kim, Won-Sa;Lee, Dong-Woo;Song, Moo-Young
    • Journal of the Korean earth science society
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    • v.21 no.5
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    • pp.563-582
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    • 2000
  • Two Cretaceous(80-90 Ma) non-marine sedimentary basins, Namyang and Tando Basins, are distributed in the Namyang area, Hwaseonggun and in the Tando area, Ansanshi, Kyungki Province, Korea. The Namyang and Tando Basins are composed of 10 facies, which are pooped into 5 facies associations(FA). FA I consists of massive conglomerate facies, normally graded conglomerate facies and reversely graded conglomerate facies, which is interpreted to have been formed by laminated sandstone facies, massive conglomerate facies(channelized), which is thought to have been formed by sheet flow, stream flow and suspension sedimentation in an alluvial/braided plain environment. FA III consists of massive mudstone(pebbly) facies, laminated mudstone facies, massive sandstone facies and is interbedded by channel-fill conglomerate. It is interpreted to have been deposited by suspension settling during flooding and channel-fill deposition in a floodplain environment. FA IV consists of massive conglomerate facies, normally graded conglomerate facies, massive sandstone facies, normally graded sandstone facies, and laminated sandstone facies and is interbedded with mudstone facies. It is thought to have been deposited by debris flow and turbidity current in a fan-delta environment. FA V consists of massive mudstone facies, laminated mudstone facies, laminated sandstone facies and is interbedded by massive conglomerate bed. It is thought to have been formed by suspension sedimentation and low-density turbidity current in a lake. In the Namyang Basin FA I is distributed in the eastern and southern margin of the basin, FA II in the middle part of the basin as north-south tending band. and FA III in the western part. In the Tando Basin FA II is distributed in the middle part of eastern margin and in the northwestern margin, FA IV in the southwestern part, and FA V in the central part. Correlation of the facies associations shows that FA I and II in the Namyang Basin are distributed in the lower to middle part of stratigraphic sequence and FA III in the upper part of the sequence whereas FA II and IV in the Tando Basin are in the lower to middle part and FA V in the upper part of the sequence. These patterns of facies associations distribution suggest that the Namyang Basin was developed as an alluvial fan and alluvial/braided plain at first and then evolved into a floodplain whereas the Tando Basin was developed as a fan-delta and alluvial/braided plain at first and then evolved into a lake environment.

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Distribution Characteristics of Quaternary Geology and Aggregate Resources in Geumsan-gun, Chungcheongnam-do (충청남도 금산군 일대 제4기 지질 및 골재자원 분포 특성)

  • Kim, Jin Cheul;Kim, Ju Yong;Lee, Jin-Young
    • Economic and Environmental Geology
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    • v.54 no.5
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    • pp.595-603
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    • 2021
  • Sand layer distribution, which is the main target of river and land aggregate resources, mainly belongs to alluvial and river sedimentary environments among the Quaternary sedimentary environments. The distribution of aggregate resources in the area of Geumsan-gun, Chungcheongnam-do is characteristically developed around a sedimentation environment in which intrusive meandering river dominate. Although the area around Bonhwangcheon Stream and the area near the confluence of small streams are small, the river floodplain develops and corresponds to the aggregate distribution area. The sedimentary layer formed in the sedimentary environment such as colluvial deposits or alluvial fan deposits has a relatively low distribution rate of aggregate resources. The vertical distribution of the Quaternary sedimentary layers in the Geumsan-gun region ranges from about 5 to 12 m and has an average Quaternary sedimentary thickness of 8 m. The aggregate-bearing section has an average thickness of 3.6 m, and the average grain size is about 21% clay-silt, 67% sand, and 12% gravel. The main characteristics of the aggregate-bearing section are that coarse-grained sand predominates, and gravel is sub-angular or sub-rounded, and the sorting is generally poor and has a massive form of deposits, and the soil colour ranges from dark grey to yellowish-brown. In Geumsan-gun, the most likely distribution area for aggregate development is the alluvial sedimentary and river sedimentary layers distributed along the current and former riverbeds of the main Geumgang River, Bonhwangcheon and small River tributaries.

Search of submarine discharge locations with multi-temporal thermal infrared images and ground radar surveys

  • Onishi K.;Sairaiji M.;Rokugawa S.;Tokunaga T.;Sakuno Y.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.685-688
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    • 2004
  • Fresh water discharge from the sea floor strongly affects a coastal ecology and the diffusion of contaminants. Much fresh water discharge has been found in the edge of Kurobe alluvial fan, in which annual rainfall is over 4000mm and there is abundant groundwater. However, it is difficult to find the groundwater discharge, thus the search of possible areas with some remote sensing tools is required. Because the temperature of the discharge point is relatively low compared with the surrounding sea water surfaces, there is a possibility to detect the area as an irregular zone of thermal infrared images. Two anomalous temperature zones, which have no surface streams from rivers, are detected by ASTER thermal-infrared images. One of them was verified as the groundwater discharge point by dives. In addition, the distribution of water table under the land side of the two areas is also detected as irregular zones by a ground-penetrating radar

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The Type of Dwelling Sites of Ancient People and Excavation-Recommended Spot in the Viewpoint of Geomorphology - 'Ohnju Region Urban Development Business Site' as an Example - (지형학적 관점에서 본 고대인의 생활터전 유형 및 시굴 추천지점 -충남 아산 '온주지구 도시개발 사업부지'를 사례로-)

  • Park, Ji-Hoon
    • The Korean Journal of Quaternary Research
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    • v.25 no.2
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    • pp.25-37
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    • 2011
  • The purpose of this study is to assume the particular area of hills where it is highly possible for historical site to be buried in the viewpoint of geomorphology and based on this to suggest excavation-recommended area. Namely, this writer is to understand the dwelling site type of ancient people who had resided there at that time for the object of 'Ohnju region urban development business site' (referred as investigation area hereinafter) and considering the characteristics of micro-landform of hills which are distributed in investigation area and is to recommend the area where it is highly possible for historical site to be buried. The result of analysis is like the following. (1) Dwelling site types of ancient people who might have resided in the whole area of investigation region are discovered to be largely 'low hills+wetland' of Type-I and 'alluvial fan(or river terrace+wetland' of Type-II. (2) In investigation area if the area which has high possibility of distribution of historical site namely, excavation-recommended area is looked as based on micro-landform unit of hills, they are Crest slope and Crest flat. Individual area ratios which Crest slope and Crest flat occupies in investigation area are 12.9% and 10.2% respectively and the rankings are 3 and 6 each. And excavation-recommended areas in valley plain(or bottomland) of investigation area are in the vicinity of 'distal end' or 'buried distal end'of small scale alluvial fan.

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